Process for the production of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl

Abstract

Provided are a 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl solution and a method for producing 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl, the 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl solution containing 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl, an aromatic hydrocarbon, and methanol, the ratio of the aromatic hydrocarbon to the methanol being 99:1 to 10:90 by weight, and the method for producing 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl including a step of crystallizing a crystal of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl from the solution.

Description

TECHNICAL FIELD

[0001] The present application relates to an improved production method of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl, which is suitable as a monomer for forming a resin (optical resin) constituting an optical member typified by an optical lens or an optical film. BACKGROUND

[0002] Resin materials such as polycarbonates, polyesters, polyacrylates, polyurethanes, and epoxides, which use binaphthyls such as 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl as a raw material monomer, are excellent in optical properties, heat resistance, and the like, and have attracted attention as novel optical materials such as optical lenses or sheets in recent years.

[0003] As a method for obtaining 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl, a method in which 1,1'-binaphthyl-2-ol is reacted with an alkylene oxide, a haloalkanol, or an alkylene carbonate is known. For example, in Japanese Patent Application Publication No. 2011-153248 (Patent Literature 1), as Synthesis Example 1 thereof, a method in which a reaction mixture obtained by reacting 1,1'-binaphthyl-2-ol with an excess of ethylene carbonate in the presence of a potassium hydroxide catalyst is dissolved in methyl isobutyl ketone, washed with water, and then subjected to desolvation at 150°C to obtain 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl in the form of a resin-like substance is disclosed. In Japanese Patent Application Publication No. 2010-18753 (Patent Literature 2), as Example 1 thereof, a method in which a reaction mixture obtained by reacting 1,1'-binaphthyl-2-ol with an excess of ethylene carbonate in the presence of a potassium carbonate catalyst in a toluene solvent is washed with a 1% sodium hydroxide aqueous solution and water, and then subjected to desolvation under reduced pressure using a rotary evaporator to obtain 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl is disclosed. However, in these methods, the target substance is obtained in the form of a resin-like concentrated residue by distilling and removing the solvent from the reaction mixture, and it is difficult to take out.

[0004] In addition, as a method for obtaining crystalline 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl by crystallization, for example, a method in which 1,1'-binaphthyl-2-ol is allowed to react with ethylene carbonate in the presence of an alkali catalyst according to the method described in Patent Documents 1 and 2, and the obtained reaction mixture is dissolved in a solvent and then cooled can be considered. However, in this method, a large amount of crystals are known to be precipitated instantaneously, becoming a state in which stirring and transportation are difficult. As a solution to this problem, the present applicant found the method described in Japanese Patent Application Publication No. 2015-168658 (Patent Document 3). In this method, crystallization is performed by reusing part or all of the mother liquor obtained from the crystallization operation of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl, thereby solving the above problem.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2011-153248

[0008] Patent Document 2: Japanese Patent Application Publication No. 2010-18753

[0009] Patent Document 3: Japanese Patent Application Publication No. 2015-168658 SUMMARY

[0010] Problems to be Solved by the Invention

[0011] However, in the method described in Patent Document 3, it is necessary to prepare the mother liquor obtained by performing operations such as crystallization and filtration in advance, and thus a production method for 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl that does not require the preparation of the mother liquor is sought.

[0012] The present application has an object to provide a production method for 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl that is more suitable when implemented on an industrial scale.

[0013] Means for Solving the Problems

[0014] The present inventors and others have repeatedly conducted intensive research in order to solve the above problems, and as a result, it has been found that the above problems can be solved and 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl can be efficiently produced on an industrial scale by causing crystals of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl to be precipitated from a solution of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl and a solvent containing an aromatic hydrocarbon and methanol in a specific ratio (i.e., performing crystallization). Specifically, the present application includes the following inventions. [1]

[0016] A 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl solution comprising 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl, an aromatic hydrocarbon, and methanol, the ratio of the aromatic hydrocarbon to the methanol being 99:1 to 10:90 on a weight basis. [2]

[0018] The solution according to [1], wherein the total amount of the aromatic hydrocarbon and the methanol is 100 to 2000 parts by weight with respect to 100 parts by weight of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl. [3]

[0020] A method for producing 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl, comprising a step of crystallizing a crystal of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl from the solution according to [1] or [2].

[0021] Effects of the Invention

[0022] According to the present application, problems such as stirring and transportation at the time of crystallization in the conventional method do not occur, and in addition, a mother liquor does not need to be prepared in advance, and a crystal of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl can be advantageously obtained even on an industrial scale.

[0023] In addition, in the present application, since a mother liquor is not required, the influence of impurities contained in the mother liquor can be avoided. Therefore, for example, in the case where it is desired to further improve the purity of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl obtained by the method of Patent Document 3, by applying the production method of the present application (so-called recrystallization is performed by the production method of the present application), it is possible to easily and efficiently improve the purity of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl obtained by the method of Patent Document 3. DETAILED DESCRIPTION

[0024] Solution of the Invention (2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl Solution)

[0025] The solution of the present application contains 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl, an aromatic hydrocarbon, and methanol in a specific ratio. In addition, the 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl contained in the solution is preferably completely dissolved.

[0026] The 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl used in the present application is obtained, for example, by a method known in the art (for example, the methods described in the above-mentioned Patent Documents 1 to 3), and is preferably prepared by the reaction of 1,1'-binaphthyl-2-ol with ethylene carbonate in terms of easily exerting the effects of the present application.

[0027] As the aromatic hydrocarbon used in the solution of the present application, for example, benzene, toluene, xylene, mesitylene, and the like can be given. Among these aromatic hydrocarbons, toluene or xylene is preferred. These aromatic hydrocarbons can be used alone or in combination of two or more. Note that, when 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl is subjected to crystallization, if only an aromatic hydrocarbon is used, stirring at the time of crystallization is hindered as described in Patent Document 3 and shown in the Examples described later, and therefore methanol needs to be used in combination. In addition, in the case where another alcohol is used instead of methanol, stirring at the time of crystallization becomes difficult as in the case where only an aromatic hydrocarbon is used, as shown in the Examples described later.

[0028] In the solution of the present application, the ratio of the aromatic hydrocarbon to methanol is in the range of aromatic hydrocarbon : methanol = 99 : 1 to 10 : 90 on a weight basis, and is preferably in the range of 96 : 4 to 20 : 80. If it is in the range of aromatic hydrocarbon : methanol = 99 : 1 to 10 : 90, in the manufacturing process described later, a state where stirring is difficult does not occur, and the crystallization of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl can be performed.

[0029] In the solution of the present application, in addition to the aromatic hydrocarbon and methanol, another organic solvent can be contained. As the other organic solvent that can be contained, for example, aliphatic hydrocarbons, esters, ethers, ketones, and the like can be given. As the above-mentioned aliphatic hydrocarbons, for example, hexane, cyclohexane, heptane, and the like can be given, as the above-mentioned esters, for example, ethyl acetate, isopropyl acetate, isobutyl acetate, and the like can be given, as the above-mentioned ethers, for example, tetrahydrofuran, dioxane, and the like can be given, and as the above-mentioned ketones, for example, acetone, 2-butanone, 4-methyl-2-pentanone, cyclohexanone, and the like can be given. In the case where another organic solvent is contained, the amount thereof is, for example, 50 parts by weight or less, and preferably 30 parts by weight or less, relative to 100 parts by weight of the total amount of the aromatic hydrocarbons and methanol in the above-mentioned solution.

[0030] In addition, in the solution of the present application, the total amount of the aromatic hydrocarbons and methanol is, for example, 100 to 2000 parts by weight, and preferably 150 to 1500 parts by weight, and more preferably 150 to 1000 parts by weight, relative to 100 parts by weight of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl.

[0031] In the solution of the present application, 2, 2'-bis (2-hydroxyethoxy) -1, 1'-binaphthyl is preferably completely dissolved. The temperature at which complete dissolution is performed is usually 40°C or higher and below the boiling point of the solvent, and is preferably 50 to 65°C.

[0032] <Method for producing 2, 2'-bis (2-hydroxyethoxy) -1, 1'-binaphthyl>

[0033] From the above-mentioned solution of the present application, by causing the crystals of 2, 2'-bis (2-hydroxyethoxy) -1, 1'-binaphthyl to precipitate by cooling the solution or the like, the stirring at the time of crystallization does not become difficult, and it is possible to produce crystals of 2, 2'-bis (2-hydroxyethoxy) -1, 1'-binaphthyl. Hereinafter, the method for producing 2, 2'-bis (2-hydroxyethoxy) -1, 1'-binaphthyl will be described in detail.

[0034] The crystals of 2, 2'-bis (2-hydroxyethoxy) -1, 1'-binaphthyl can be caused to precipitate by cooling the solution of the present application to a temperature that is 15°C lower than the temperature of the above-mentioned solution of the present application, and specifically, cooling is usually performed to 25 to 45°C, and preferably 30 to 40°C. Note that the cooling is usually performed by standing cooling or slow cooling. In addition, as necessary, by adding a seed crystal at a prescribed temperature, it is also possible to cause the crystals to precipitate. After the crystals have precipitated, as necessary, an operation of maintaining the crystals at the same temperature for a certain period of time to cause the crystals to grow can be performed, or further cooling can be performed.

[0035] For the crystallization solution containing the crystals of 2, 2'-bis (2-hydroxyethoxy) -1, 1'-binaphthyl thus produced, a solid-liquid separation operation is subsequently performed, whereby the crystals are recovered. As the solid-liquid separation operation, for example, a filtration operation using a centrifugal separator, a filter press, a suction filter, or the like can be cited, and a centrifugal separator is industrially preferred. Then, for the recovered crystals, as necessary, washing using a solvent or the like can be performed, or drying can be performed. In addition, as necessary, further purification such as adsorption / re-crystallization can be performed.

[0036] Example

[0037] Hereinafter, the present application will be specifically described using examples and the like, but the present application is not limited by any of them. Note that various measurements were performed by the following methods. In addition, in the following examples and the like, unless otherwise specified, the yield is the tangible yield of (RS) -2, 2'-bis (2-hydroxyethoxy) -1, 1'-binaphthyl with respect to (RS) -1, 1'-binaphthol used in the reaction, and the HPLC purity is the area percentage value of HPLC measured under the following conditions.

[0038] <Conditions for HPLC measurement>

[0039] Apparatus: SHIMADZU LC-2010A

[0040] Column: SUMIPAX ODS A-211 (5 μm, 4.6 mmφ x 250 mm)

[0041] Mobile phase: water containing 0.03% trifluoroacetic acid / acetonitrile containing 0.03% trifluoroacetic acid (acetonitrile containing 0.03% trifluoroacetic acid 30%→100%)

[0042] Flow rate: 1.0 ml / min, column temperature: 40°C, detection wavelength: UV 254 nm

[0043] Example 1

[0044] Into a glass-made reactor equipped with a stirrer, a condenser and a thermometer, (RS)-1,1'-binaphthyl-2-ol 50 g (0.175 mol), ethylene carbonate 35 g (0.401 mol), potassium carbonate 2.5 g and toluene 50 g were charged, and stirred at 110°C for 8 hours, whereby a reaction mixture containing (RS)-2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl was obtained.

[0045] After dilution by adding toluene 180 g to the obtained reaction mixture, the organic solvent layer containing the reaction mixture was kept at 85°C while stirring, and washed with an aqueous sodium hydroxide solution. Next, the organic solvent layer was washed with water until the washing water became neutral, and the obtained organic solvent layer was dehydrated under reflux. Next, after cooling the organic solvent layer to 60°C, methanol 21 g was added, and a crystallization solution was obtained. After cooling the crystallization solution to 39°C, crystals were precipitated by keeping at the same temperature for 1 hour, and further cooled to 2°C, whereby a crystallization mixture was obtained. The obtained crystallization mixture was stirrable.

[0046] The precipitated crystals were filtered, washed with toluene 35 g twice, and dried under reduced pressure at 80°C, whereby white crystals of (RS)-2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl 53 g (yield: 81%, HPLC purity: 99%) were obtained.

[0047] Example 2

[0048] In Example 1, the amount of toluene added to the reaction mixture was set to 246 g, and otherwise, the same as in Example 1 was performed until dehydration under reflux, and then the organic solvent layer was cooled to 60°C, methanol 12 g was added, and a crystallization solution was obtained. After cooling the crystallization solution to 45°C, crystals were precipitated by keeping at the same temperature for 1 hour, and further cooled to 2°C, whereby a crystallization mixture was obtained. The obtained crystallization mixture was stirrable.

[0049] The precipitated crystals were filtered off, washed twice with 35 g of toluene, and dried under reduced pressure at 80°C to obtain white crystals of (RS)-2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl 53 g (yield: 81%, HPLC purity: 99%).

[0050] Example 3

[0051] In Example 1, the amount of toluene added to the reaction mixture was set to 16 g, and otherwise, the same as in Example 1 was performed until dehydration under reflux, and the organic solvent layer was cooled to 62°C, and methanol 263 g was added to obtain a crystallization solution. After the crystallization solution was cooled to 31°C, the crystals were precipitated by keeping the temperature for 1 hour, and further cooled to 2°C to obtain a crystallization mixture. The obtained crystallization mixture was stirrable.

[0052] The precipitated crystals were filtered off, washed twice with 35 g of toluene, and dried under reduced pressure at 80°C to obtain white crystals of (RS)-2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl 52 g (yield: 79%, HPLC purity: 99%).

[0053] Example 4

[0054] In Example 1, the amount of toluene added to the reaction mixture was set to 16 g, and otherwise, the same as in Example 1 was performed until dehydration under reflux, and the organic solvent layer was cooled to 64°C, and methanol 33 g was added to obtain a crystallization solution. After the crystallization solution was cooled to 39°C, the crystals were precipitated by keeping the temperature for 1 hour, and further cooled to 2°C to obtain a crystallization mixture. The obtained crystallization mixture was stirrable.

[0055] The precipitated crystals were filtered off, washed twice with 35 g of toluene, and dried under reduced pressure at 80°C to obtain white crystals of (RS)-2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl 56 g (yield: 85%, HPLC purity: 99%).

[0056] Example 5

[0057] In Example 1, the amount of toluene added to the reaction mixture was set to 896 g, and otherwise, the same as in Example 1 was performed until dehydration under reflux, and the organic solvent layer was cooled to 60°C, and methanol 39 g was added to obtain a crystallization solution. After the crystallization solution was cooled to 30°C, the crystals were precipitated by keeping the temperature for 1 hour, and further cooled to 2°C to obtain a crystallization mixture. The obtained crystallization mixture was stirrable.

[0058] The precipitated crystals were filtered off, washed with toluene 35 g twice, and dried at 80°C under reduced pressure to obtain white crystals of (RS)-2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl 37 g (yield: 57%, HPLC purity: 99%).

[0059] <Comparative Example 1>

[0060] In Example 1, the amount of toluene added to the reaction mixture was set to 1264 g, and otherwise, the operation was performed in the same manner as in Example 1 until the dehydration step under reflux, and then, when the organic solvent layer was cooled to 30°C, the crystals precipitated at once, and stirring became difficult.

[0061] <Comparative Example 2>

[0062] The same operation as in Example 1 was performed until the water washing step, and then, the obtained organic solvent layer was concentrated, and water and toluene were distilled off. After methanol 217 g was added to the obtained residue, the temperature was raised to 62°C, and the crystals were completely dissolved. Next, when the obtained solution was cooled to 35°C, the crystals precipitated at once, and stirring became difficult.

[0063] <Comparative Example 3>

[0064] The same operation as in Example 1 was performed until the dehydration step under reflux, and then, the organic solvent layer was cooled to 62°C, and ethanol 21 g was added to obtain a crystallization solution. When the crystallization solution was cooled to 45°C, the crystals precipitated at once, and stirring became difficult.

[0065] <Comparative Example 4>

[0066] The same operation as in Example 1 was performed until the dehydration step under reflux, and then, the organic solvent layer was cooled to 66°C, and 2-propanol 21 g was added to obtain a crystallization solution. When the crystallization solution was cooled to 55°C, the crystals precipitated at once, and stirring became difficult.

[0067] <Comparative Example 5>

[0068] The same operation as in Example 1 was performed until the dehydration step under reflux, and then, the organic solvent layer was cooled to 82°C, and 1-butanol 21 g was added to obtain a crystallization solution. When the crystallization solution was cooled to 53°C, the crystals precipitated at once, and stirring became difficult.

Claims

1. A 2,2'-bis(2-hydroxyethoxy)-l,l'-binaphthyl solution comprising 2,2'-bis(2-hydroxyethoxy)-l,l'-binaphthyl, an aromatic hydrocarbon, and methanol, the aromatic hydrocarbon being at least one selected from the group consisting of benzene, toluene, xylene, and mesitylene, the ratio of the aromatic hydrocarbon to methanol on a weight basis being aromatic hydrocarbon : methanol = 99 : 1 to 10 :

90.

2. The solution of claim 1, wherein, The total amount of the aromatic hydrocarbon and methanol is 100 parts by weight to 2000 parts by weight with respect to 100 parts by weight of 2,2'-bis(2-hydroxyethoxy)-l,l'-binaphthyl.

3. A method for producing 2,2'-bis(2-hydroxyethoxy)-l,l'-binaphthyl, comprising a step of crystallizing a crystal of 2,2'-bis(2-hydroxyethoxy)-l,l'-binaphthyl from the solution according to claim 1 or 2.